Getting Started with Gauntlets

I keep putting off actually building gauntlet dungeons.  I've been thinking a little about why that is.  What are the hard problems here that I've quietly, subconsciously hemming and hawing over for like two years now?

One troublesome thing is that I feel like if I'm going to build levels that test the presence and effective use of certain classes, I should keep those levels sort of "balanced" between each other, so that certain classes don't feel like they're useless.  This almost implies a horizontal dungeon structure - if class-check levels are in series with descending dungeon level, then some class is still going to feel shafted or "dependent" on another class to get them down to where they shine.  And this also dilutes the viability of weird party comps which I was hoping for from class-focused levels.

I'm not really sure how I feel about building "wide" dungeon levels with sublevels testing individual classes.  Maybe this is an overreaction to being burnt on Rathell, the widest single level I've ever run.  I'm not sure how much patience / tolerance players will have for a single level of difficulty, even if it presents somewhat varied challenges.  On the other hand, it might make finding a path down more special (or more intimidating).

One solution to these two concerns / conflicting requirements is thinking more finely-grained about class-check levels and mixing class checks within single, smaller levels.  Rather than making a level (for example) a thief check or a cleric check, throw in individual elements that are cleric or thief checks.  A level might have a bunch of locks and a bunch of shriekers, testing thief for open locks and cleric for silence, or it might have a bunch of traps and undead, checking thief for trapfinding and cleric for turning (or cleric for find traps...).  So thinking about classes as bundles of features that are individually tested, and making testing multiple classes within a single level the standard.

This sounds pretty easy for thief, MU, and cleric - thief has a bunch of skills (which "come online" at varying rates), and MU and cleric have huge banks of spells to test individually.  Fighter is the tough one.  Clerics can pass AC checks just as well as the fighter, thieves can pass magic sword checks just as well as the fighter.  Cleaving checks (if one's game even has cleaves) are often passable by MUs with sleep, fireball, etc.  Max HP is a strange thing to test; I guess you could kinda do the 5e death spell thing, conditioning effects on max HP?  Rejigger sleep and cloudkill to work off of max HP rather than HD?  That's actually a really funny thought.  Conditioning effects on a 4e-style "bloodied" status when people are at half, so having bigger HP pools changes when those effects kick in?

I suppose one thing fighters are likely to have that most other characters will neglect (or at least not be raising through ability score tradeoffs) is just brute Strength.  Bring out the stuck doors, the portcullises that need lifted, the columns that need toppled, the stones that need carried, the chains that need pulled or broken.  This idea is growing on me - what sort of funhouse dungeon is complete without some strongman competition events?  So your MU has ogre power, fine, it's only three turns, Fafhrd here can flex those thews all day long.

Another angle on classes, if one were to build multiple smaller (say) 3-level dungeons, would be to tightly-class-theme individual dungeons.  Then you're not blocked on getting to the Thief Level by having to pass the Cleric Level.  And it's a pleasing idea from the in-world perspective; the legendary thief is gonna build a three-level gauntlet of traps and locks and sheer walls to make sure that whoever gets his gold is a worthy successor, you know?  The ruined temple of the Krolm is a gauntlet of strength and hit points and cleaving, it will take a lot of lore and prep to get into the sanctum of the Old Archmagos, etc.  The undead angle on clerics is a bit odd; maybe it's what is being kept in rather than out.  Or holy places with features intended to keep the unfaithful out have fallen to darkness.

Returning to "test multiple class features within a single megadungeon level", though, the other difficulty I have is in the very first level of a gauntlet megadungeon, for completely new players.  You just know their party composition is going to get messed up by casualties and you might not want them to rely on hirelings to patch it up.  I would almost be tempted to put "big scores" behind checks on individual class "core feature" like sleep and turning - getting a cleric or MU to the right place and recognizing that that's the right time (eg, to not have blown your sleep on a piddly random encounter) is a good start and a behavior we want to reinforce.  Other than that, maybe fundamentals of practice are the thing to focus on, like basic mapping?  A caller check, around "can the caller successfully interrupt impulsive players about to do something stupid?"  Maybe checks on mundane gear are also a good theme; most of that stuff is well within the purchasing power of first-level characters and mundane gear checks aren't dependent on having any particular class still alive.

Maybe that's an interesting solution to the first-level problem.  For seasoned veterans, a dungeon level with few monsters focused on mundane gear "puzzles" could be a bit dull.  But for people who have never played before, just successfully executing on the basics of dungeon exploration and random encounters could be a stimulating challenge even without having to worry about tackling serious (eg humanoid) lairs.

So then maybe the second level introduces humanoid faction play and gets more serious about mapping, logistics, traps...  What would be a good "capstone" for a three-level 'tutorial' gauntlet dungeon, I wonder?

Traveller and Cruising

It's possible I've been thinking about Traveller all wrong.  Maybe this is obvious to everyone else but here goes.

I've been reading some books about maritime cruising.  "Living for extended time on a vessel (yacht) while traveling from place to place for pleasure. Cruising generally refers to trips of a few days or more, and can extend to round-the-world voyages." There's a lot of discussion about how to do your own maintenance (one, because stuff breaks at sea, and two because hiring professionals to do it in port is really expensive) and how to do odd jobs to make some money on the side since you probably aren't regularly employed.  Some of those odd jobs and cruising stories sounded like the sort of things Traveller patrons would ask for, and here we are.

This lens makes a lot more sense for Traveller than "space trucking".  You don't have to explain the economics of small-scale shipping, because that's not really what is happening here.  Sure you might make a windfall on cargo every now and then (and cruisers attempt this too, with mixed success - "We were told that people in the Marquesas desperately needed reading glasses.  I bought 50 pairs in Mexico and still have all of them [because we were misinformed].") but that's not why you're traveling.  You're traveling for its own sake, and money is a means to the end of continuing to travel.  You're not out to get rich - just to keep funding the midlife crisis and not have to go back to a day job with a boss and a commute. This is why your "career" ends at the end of chargen.

It's interesting to compare with the similarly non-accumulative style of Appendix N, where the heroes adventure to get rich, only to spend it all and then need to adventure again.  Here too it's adventuring for money in order to maintain an unconventional, expensive but unencumbered lifestyle.

I think this view is consistent with the belief that money is supposed to be important in Traveller, but it also admits the Classic Traveller style where PCs having a ship is somewhat rare.  A Traveller without a ship can still work odd jobs in / for the "cruising" community and get working passage to wherever. Losing the money game doesn't end the campaign; it just changes it temporarily.  So the money pressure maybe shouldn't be as overwhelming as it might traditionally be with the starship loan (or you do what many budget cruisers do and get a really old vessel).  It's there to keep things interesting, to add a creeping danger that you can't just run from, not to be the focus of play.

This cruising lens also answers the question of "why do we have a baronet or an ex-admiral on this grungy little vessel?"  They're not loading cargo - they're just drifting.  Plenty of nobles are into sailing ("It seems that of any activity in the world, singlehanded sailors have the best odds of being knighted.") and the admiral retired and decided he just wanted to kick back in the tropics in a low-stress environment but can't help but get himself into trouble.

Some possible implications for DMing Traveller - NPCs from the cruising community.  Lots of cruising vessels have "buddy boats" or form regattas headed to the same place at the same time.  This is good for when something goes wrong.  The vessel at the next berth over in port isn't a rival small trader; they're drifting hippies with a hydroponic weed operation onboard, or a very trad religious husband who used to sell insurance with wife and four kids and a dog aboard, or a reclusive ex-programmer with a bunch of ship systems automated, or a husband/wife pair where the husband is a professional hunter and the wife is a xenobiologist (who is actually the better shot of the two), or...  There's just a ton of room for recurring, charmingly-eccentric NPCs here, who might fill the patron role when things are going well for them, or who might need rescued when something goes wrong.

Another implication for DMing Traveller regards building sandboxes.  When the players are out to do the "space trucking" thing, you have to be really careful to not set up Golden Pairs of planets with complementary economic tags where you can just go back and forth indefinitely and make tons of money.  But if the players are on board with the game being about drifting, you might be able to be less careful with this; it becomes a "sometimes food", because anything that resembles routine work is anathema.  It seems like a way of thinking about the game that would really encourage building a sandbox with lots of wild, interesting bits for your tourists to go see and mess with.  It could be much mellower than the highly-incentivized OD&D sandbox of "where do we go to make a ton of money, hence XP, as quickly and safely as possible?" which so often causes analysis paralysis for optimizers (as does the Space Trucker optimizing his routes).  But cruising Traveller admits satisficing; "sure that sounds like an interesting place to go, uhhh I wonder if they need any eyeglasses, maybe we can make a buck.  Any passengers headed that way to defray our costs?"

Coastal Sailcrawling?

Part of the reason things have been quiet here lately is that I was taking a course on navigating vessels under sail in coastal waters, which pretty well ate my weeknights.  At the beginning I was looking at doing a "Notes from a $TOPIC course" series like I've done previously with some courses [1][2] but it got away from me.  So, having arrived, now reflecting.

One conclusion from spending a lot of time staring at charts and plotting courses with pencil, compass, and protractor is that there is definitely room for procedure and gameplay in modeling this.

I think the distinction between coastal and open-water navigation is probably under-appreciated in Trad D&D's "waterborne adventuring" rules.  I don't know much about long-distance open-water passagemaking yet but reading accounts from eg Slocum it doesn't seem crazy to abstract down to "n days pass, have a couple random encounter rolls, you arrive more-or-less where you were planning to" given reasonably-intelligent play like using the trade winds and celestial navigation.  You can definitely get screwed and capsized by a big storm in the open sea, but there aren't many things to run into.  The coast, on the other hand, is by definition something you can run into.  To paraphrase one old salt, "the sea is pretty safe; it's the land that will get you".  Coastal vs offshore is probably also a useful line for ACKS' rule about continuing to sail through the night with a navigator - at night in open sea, by all means, get out your sextant, take some bearings on some stars, and sail on.  At night in unfamiliar, medieval coastal waters without lighted buoys, an accurate chart, or a full moon...  probably wiser to drop anchor and wait for dawn.

On a 1:80000 scale coastal chart like Chart 1210TR, one inch is about one nautical mile (some nuances apply due to Mercator projection but good enough for gaming work).  A small vessel under sail typically makes about 6 knots.  So if you do 1-inch, 1-nautical-mi hexes, you get a 10-minute turn to move one hex.  Or you go up to one-hour turns with 6 hexes per turn.  Either way, you also probably want to apply current smeared across the hour; if sailing in a 3kt current, you get pushed one hex current-ward every 20 minutes.  Since we're stealing a real-world chart, we can go dig up published tidal current tables.

Putting it on hexes is also kinda reasonable for dealing with wind direction and tacking; pick (or roll) one of the six hex directions for the wind to be coming from, and moving directly in that direction costs double (assuming you're making multiple short tacks within a single hex).  A modern sloop-rigged boat usually wants to sail at least 45 degrees off the wind, and then there's some leeway so you're going to do a bit worse than 45, often more like 50-55 in significant winds, sometimes much worse in big winds.  60 degrees off the wind is probably quite optimistic for medieval sailing vessels but if you're running a post-apocalyptic setting where not everything has been forgotten, primitive sloops sailing 60 degrees off the wind seems workable and simple.  Roll again every hour to see if the wind has shifted direction or remains from the same direction (or if it dies entirely, leaving them at the mercy of current - which is how many boats without motors end up on the rocks).

The other side of tide from current is depth.  A 1-mile hex probably admits multiple depth soundings.  If the party is sailing in a hex where there are spots with a depth less than their draft, there's a chance they run aground.  This seems basically like the "roll a d6 to see if the trap fires".  Use your judgement of what fraction of the hex is very shallow to determine the probability they end up in it.

If shoals are traps, tidal straits (also called tidal gates) are doors.  These are narrow channels through which tidal currents are very strong.  Examples include the Golden Gate in San Francisco, Hell Gate in New York, and Deception Pass in Puget Sound.  If you try to pass the wrong way through one of these at the wrong time, currents can be more than four knots and you make very little progress.  So they're like doors that only open at certain times.

Finally, how do players actually navigate a coastal sailbox?  They don't have a chart, and there are probably not lighted buoys in your setting.  There might be lighthouses, and if they have a hand-compass you can give them a rough bearing.  The various tall points of reference typically on coastal charts, like radio towers, water towers, and church steeples could be readily translated into towering keeps, wizards' towers, and hilltop monasteries for your players to go Full Lindesfarne on.  Chart 1210TR includes "monument" and "Chilmark Spire" points of reference - I'm not exactly sure what the Chilmark Spire actually is but it's rather evocative, no?  Again, in a post-apocalyptic setting, city areas could be readily translated into ruins.  Headlands, steep coastal bluffs, and the edges of particular islands also seem like commonly-used points of reference for inshore work.  We have, in the language and reference points of actual navigators, pieces for a language of wilderness play.

One may readily ask - why bother / will there be interesting gameplay here?  I think so.  Looking at the structure of river deltas, barrier islands, and sounds, there are lots of tiny islands and the structure of the water-network comes highly-Jayquayed by default.  A small island is kind of like a room; it is self-contained and you can stock it as a unit and the party can anchor the boat and row ashore and explore it and interact with the stocked thing.  And then your waterways are sort of like treacherous hallways, and your sheltered bays are places to rest at anchor. 

 

Just look at all those islands

 

In conclusion, perhaps deltas and barrier island chains may be thought of and played as dungeons, open sea as wilderness.

Solving First Level - Resting in the Dungeon?

The natural product of two recent lines of thinking - figuring out how first level is "meant" to be played, and monsters that counter resting in the dungeon.

Notably, in Moldvay there really aren't any monsters on the first dungeon level's wandering monster table who hard-counter resting in a room where you've secured the door.  This means a first level party with only one sleep a day actually has a lot of leeway to recover that critical spell.  Traverse the dungeon to the stairs to the second level, hole up and recover the sleep if you had to use it to get there, go down to the second level and look for unguarded treasure, pop back up when you've spent the sleep and recover it safely near the top of the stairs...

Your ability to take out a lair is still quite limited, since your max sleeps per day is still only one, but your ability to survive wandering monsters is much improved.  And then rations and water become a limiting factor on the duration of your dungeoneering expeditions - though camping in pitch blackness in a sealed room in a haunted underworld certainly sounds...  demoralizing.  Not that torch smoke in an enclosed space sounds much better.  You start out with torches and fresh rations and then upgrade into lanterns and iron rations as you get the money for them...

There are probably amusing tradeoffs in waste management too - a 12-person party produces a fair bit of excrement per day.  If you leave it lying around it might attract vermin and molds.  If you pack it out with you then it costs encumbrance and might attract monsters with strong senses of smell.  Dare you use the dreaded dungeon bathroom, based on real FLGS bathrooms?

Oozes and Other Bunker-Buster Monsters

There was a discussion on the osr subreddit the other day about players resting in the dungeon, and it occurred to me that if you iron spike or bar a door shut so you can rest but roll an ooze on the wandering monster table while resting, it might just be able to get through under/around the door and disrupt your sleep.

Thinking about whether there were other types of monsters that could do something similar, incorporeal undead and swarms also spring to mind.  Maybe vampires if you let them go gaseous voluntarily.  Any of your burrowing enemies like ankhegs, grey worms, purple worms, thoqqas, and xorns, though those will mostly be loud and noticeable.

There's an interesting parallel with Deep Rock Galactic here, where they introduced several enemies (the bulk detonator and the oppressor) explicitly to counter the strategy of building bunkers.  These enemies can "force the door" by digging and are either difficult to damage from the front or explode massively.  It kinda makes me wonder whether some of these classic D&D monsters that might plausibly pass through doors were originally developed as counters for resting in dungeons.

I think this has interesting implications for how you build random encounter tables for dungeon levels.  If there's a "bunker buster" monster on your table, then the party is at risk of having their sleep disrupted if they barricade-and-rest on that level.  I went looking for AD&D 1e's tables but still haven't found them.  In OD&D Book 3, there's only the Ochre Jelly on the 3rd level table (though there sure are a lot of MUs who might be able to knock in a door).  Moldvay / OSE is much more interesting through this lens, with the following levels container the following potential bunker-buster monsters:

1. Nothing really (green slime isn't motile so doesn't count)
   
2. Grey Ooze.  Pixies hiding in the room you're bunkering in to prank you in your sleep would be pretty funny but I'm not sure it really counts.
   
3. Ochre Jelly and Shadows (Gelatinous Cube too but it probably can't fit under doors?), Basic Adventurers potentially
   
4. Grey Ooze, Ochre Jelly, and Wraiths.  Rust monsters too, depending on how exactly you do your spiking.  Expert Adventurers also possibly.
   
5. Black Pudding, Ochre Jelly, Spectres, Expert Adventurers, possibly White Dragon
   
6. Black Pudding, Purple Worm, Vampire, Expert Adventurers, possibly Red Dragon.
   

By the end there a solid quarter of possible wandering monsters are possible bunker-busters.  But holing up in the top levels of the dungeon is probably pretty safe!

If players quietly rest 8 hours in the dungeon, they'll get 3 wandering monster rolls per hour, or 24 total rolls.  Since the probability of a monster on each roll is 1 in 6, you expect four wandering monsters.  So if a quarter of your table for a given level is bunker-busters, then resting will usually fail.

ACKS has heuristics for building dungeon wandering monster tables, with one-third beastmen, one-third mindless/animals, and one-third "men and monsters".  It would be interesting to add a heuristic around bunker-busting enemies as well.  If you have one on a 1d12 table, then it won't come up in 70% of rests (assuming 4 wandering monsters are rolled; there's a long tail of bad luck in the wandering monster checks).  Two out of 12 means something gets through the door in 52% of rests.  At three out of 12, the door only holds in 32% of rests.  I think I kinda like 2 in 12 - you can do one ooze and one incorporeal undead, swarm, or burrower, so there's some variety, and rests are pretty close to a fair 50/50 shot.  Or if you count Rival Adventuring Party, then the interruption isn't necessarily unfriendly, but it might still be an interruption.

Surviving Fifth Level: The Heist Hypothesis

In another instance of recording bright things people have said in the ACKS discord, Arbrethil had some thoughts in response to Surviving First Level: The Heist Hypothesis and since he still hasn't started a blog (hint hint), I guess I'll record it here.

My players often break your assumptions (hiring lots of henchmen) [ed:to be fair, this is Moldvay's position and I'm just trying to solve it], but I've also definitely seen heist type play happen.  And I think when it does, it's often in the wilderness, where treasure hauls are bigger and random encounters are checked less often.  Certainly the odds of winning a wilderness fight are worse, but evasion lets you get away most of the time if it's not a fight you want.  And if you can find a good lair - stupid ogres that you can distract and bamboozle, or a lone dragon that can't both pursue pesky adventurers and guard its lair - that can be enough to level the thief on its own.  The other piece of the puzzle that stands out to me is the utility of a massed spear charge. Even if only three of your five characters can make a spear charge, if you win initiative you've got solid odds of cleaving through a dungeon-sized band of beastmen.  Once you can hire a few additional characters, a high AC PC-led dungeon phalanx trumps most any random-encounter sized band of beastmen on dungeon levels 1-2 even without magic support.
So I think your analysis of them going down to 2nd level pretty much checks out, and wilderness heists are like that but in every way moreso.

Emphasis mine.  I think the points about spear charges and high-AC phalanxes are good ones in ACKS specifically, though spear-charges can also work against the players if they encounter organized and appropriately-armed opponents.  The really interesting point (and one which cuts across both ACKS and OSE/B/X) is that that low-wilderness-level play is often very heist-like.  My Bjornaborg game was very treasure-map-centric once it got into the wilderness levels; get to the treasure, kill whatever's guarding it (if anything), and get back to town with it, avoiding encounters whenever possible.  And intuitively, it seems like there should be some parallels between low-dungeoneering-level and low-wilderness-level play, in that you don't have all the tools for either yet, under a theory of spell/class design where new abilities tend to be appropriate for the phase of the game where they become available.  To gather intel, you don't have Invisibility at 1st, and you don't have Wizard Eye at 5th.  To slow pursuit, you don't have Web at 1st, and you don't have Wall of Fire at 5th.  So it sort of makes sense that a style of play appropriate to the early-dungeon phase might re-appear in the early-wilderness phase, because you're in a similar lacking-tools situation.

This might also have something to do with my players' frustration with low-wilderness play.  I have never run 1st level before.  They've never played 1st-level OSR games before.  So we've never had to "solve" 1st level.  Hence, having to learn 1st level's lessons at 5th level instead.  But by 5th, you're more invested and the stakes are much higher; if you're learning heist play at 1st and you mess up, oh well, new characters are easy.

I wonder if this is the whole root of the problems I've been having with running wilderness game for literally a decade at this point.  It would be pretty funny if for all my theorizing about wilderness as dungeons and hiding maps and resource models and microsandboxes, the real answer was "make sure your players have had to survive 1st level."  A simple, practical, culture-of-play thing with unexpected consequences being the answer would be so perfectly on-brand for the OSR that I wouldn't even be mad.

But since, we're here and theorizing - there are some important differences in the resource model between 1st in the dungeon and 5th in the wilderness.  Fireball is pretty analogous to sleep - except that often in the wilderness you can regain fireball most days.  So that's a tremendous difference in your ability to deal with repeated encounters in a single expedition.  On the other hand, there's still some similarity in tackling lairs; one fireball isn't going to win a wilderness humanoid lair fight any more than a single sleep is going to win a dungeon lair fight.  And this is what drives the back to the heist dynamic - it's really about inability to take lairs head-on, since that's where the treasure (hence XP) is.  On the other hand, the ability to replenish fireballs daily opens up Fabian options for gradual lair reduction during a single expedition not available in the dungeon at 1st level.

The mercenaries-and-hirelings situation also bears examination through this lens.  Mercenary troops in the low wilderness levels probably serve about the same function are hirelings at 1st level; you're not going to be able to acquire and finance enough of them of high quality to rely on them alone to take out humanoid lairs, but they can even your odds against humanoid encounters, and at least help hold the line, pin the humanoids, and help prevent you from being overrun.  I'm really curious whether Moldvay would push against the use of mercenaries in the low wilderness levels in the same way he pushes against hirelings right out of the gate, so that players learn to do without them rather than using them as a crutch.  It seems worth considering to me; we certainly had fights in low-wilderness that my players "cheesed" with massed troops and then I got butthurt and wrote a long post about it.  I guess maybe I should go read Expert and see if Moldvay expresses an opinion on this.

In any case - thanks again Arb for pointing this parallel out!

Snakebites and Magic Rocks

Or, I spent 15 hours reading wikipedia pages on venomous snakes so I guess I may as well make a post out of it.

https://xkcd.com/761/

I am not a herpetologist.  I am not your herpetologist.  Nothing in this post should be construed to be medical advice, nor expected to be perfectly accurate.  Everything here is gross generalizations for the purposes of gaming.

The two big families of venomous snakes dangerous to man are the elapids and the vipers (there are some dangerous ones in other families like the colubrid boomslang though)

• Elapids
• Include cobras, taipans, sea snakes, coral snakes, kraits, mambas, pretty much all of the various intensely venomous Australian snakes with unassuming names like the Western Brown Snake...
  
• Often relatively long and thin body form 
• Mostly have round pupils
• Mostly lay eggs
• Have relatively short, non-folding fangs at the front of the mouth
  
• Venom is often primarily neurotoxic and kills by stopping respiration
• In some cases, venom is almost entirely neurotoxic in action and causes no pain or swelling at the bite site, making it hard or impossible to tell if a bite was "dry" until onset of symptoms
• The combination of short fangs and quick-acting venoms often lead to an attack pattern against their primary prey of wrapping around and biting multiple times to guarantee some good deep killing envenomations
• Hunting pattern is often active - seeking out prey, going into burrows
  
• In humans, time to kill from a wet bite is often 30 minutes to six hours
  
• Vipers
• Include rattlesnakes, copperheads, cottonmouths, adders, pit vipers, bushmasters, fer-de-lance, ...
• Pit vipers are called this because they have a pit on each side of their head between the eye and the nostril which can sense infrared, not because they live in pits.  It's actually a pretty big category and includes most (all?) New World vipers
  
• Often relatively stocky/girthy/thicc body form 
• Many have slit-pupils like cats
• Mostly give birth to live young
• Have long, thin fangs that fold up against the roof of the mouth when not in use, and lower jaws that hinge out past 150 degrees to let them strike with the long fangs
• Venom is often primarily toxic to blood and muscle tissue, causing clotting, hemorrhage, blistering, necrosis, kidney failure from rhabdomyolysis.  May require amputation of the bitten limb even if it doesn't kill you.
  
• I have now seen some pictures of necrotized viper bites that I cannot unsee
• Wet bites are typically very painful and swell up
  
• Between the fragile but long-reach and deep-injecting fangs and the slow venoms, attack pattern against primary prey is often a single lunging bite and then backing off and waiting for the prey to die.
• Some can track bitten prey by the smell of some components of the venom acting on the prey's blood
• Often a passive hunting style, waiting in ambush for passing prey to tag
  
• In humans, time to kill from a wet bite is often 10+ hours (overnight or the next day) unless the bite was onto a vein  

On reflection, it seems like regular-sized mundane venomous snakes are really more like traps than they are combat encounters.  You didn't poke the pile of leaves with a 10' pole before you stepped in it, save vs poison, and unless you roll a 1 you still have at least half an hour to get a Delay Poison or Neutralize Poison in before you keel over.  The necrosis angle on viper bites could be somewhat interesting, might play out a bit like ACKS' Dismember spell on a failed save.  2HD for a 5' pit viper that probably weighs 5 pounds seems really high.

Where you'd expect to see save-or-die poison with a pretty quick time to kill would be in snakes for whom humans are a common prey species.  I recall reading somewhere that most predators hunt prey that is something like a 10th of their own mass to minimize the risk of being injured by the prey.  I don't know how true this is but it sort of passes the smell-check; a mouse is much smaller than a cat, a mosquito is much smaller than a bat or sparrow, a seal is much smaller than a great white shark.  I would expect pack hunting, ambush, and venom to all shift those closer to 1:1, since these strategies reduce the risk of injury to the predator.

The Eastern Diamondback Rattlesnake is typically about 6 feet long and weighs about 5 pounds.  It commonly preys on cottontail and marsh rabbits, which weigh about 2-3 pounds.  Scaling up mass with the cube of any single dimension, we'd expect a 12 foot rattlesnake built to the Eastern Diamondback's proportions to weight about 40lbs, and a 24-foot rattlesnake to weigh about 320.  That seems a size at which hunting adult humans as a primary prey sounds plausible.  Incidentally, this is also about the size of a large reticulated python, which have been known from time to time to prey on humans, including adult male humans.  I think this length and mass would be a better match for the 4HD giant rattler stats than the 10' in its description.

Anyway, a few other fun snake "facts":

• King cobras have a really low-pitched growly hiss apparently
• The yellow-bellied sea snake can get about 33% of its oxygen needs by absorbing oxygen from the water through its skin
• We're pretty sure sea snakes don't drink seawater, but nobody is really sure where they get fresh/brackish water.  It's theorized that they might drink the layer of brackish water at the top of the water column during heavy rains
  
• The small-scaled burrowing asp can rotate its fangs sideways out of its mouth and uses this in confined spaces where it doesn't have room to bite.  It has also been observed to sting each rodent in a burrow containing multiple before stopping to eat any of them.  Next time your players meet a snake and complain that trying to bite each PC in turn was too smart, show them this.
  
• Some venomous snakes which hunt by ambush use "caudal lures", where the tip of their tail look like a tasty worm or grub.  A dungeon-snake whose tail looks like some sort of unattended treasure would be pretty funny.
  

I also wandered into some articles on treating snakebite.  Antivenin is made by injecting large mammals like horses with small doses of venom and then harvesting their antibodies.  Antivenom can have some pretty significant side effects, called "serum sickness", from reactions to horse proteins.  These can take up to two weeks to appear and in rare cases can kill you.  In folk medicine, there's a whole genre of magic healing stones, some of which nominally work on snakebites (bezoar stones from inside of toads and snake-stones or black-stones often made from burnt animal bones) and some of which might be made by snakes (adder stones).  There were also madstones, which might not have been stones at all but body parts of albino deer used to try to treat rabies?  In conclusion I feel OK about having some non-magical treatments for snakebite that give you a second save but also entail bed rest afterwards.